Physical Properties: Irish Blue Limestone

Mc Keon Stone Ltd - Threecastles Quarry, Kilkenny

The Irish Blue Limestone is a natural material and the physical properites reflect the conditions under which the stone originally formed and the subsequent geological history of Ireland. The best guarantee for the stone is its successful use as a building material in Ireland during the last 3000 years and the fact that many of the older structures built with it are still standing.

Today engineers and architects normally seeks to confirm the suitability of the stone by using a range of tests to quantify what are considered to be the important physical parameters of the material. Unfortunately, because the material is not synthetic, random variation is inevitable both within a single bed and between different levels within a single quarry.

The Irish Blue Limestone from the Threecastles Quarry , Co Kilkenny has been tested by a wide range of laboratories in a number of countries during the last 15 years and the test results below are from January 2005 . Over the years there is little variation in the periodic test results taken .

Where certain properties of the stone are of paramount importance to a particular project, the various International Standards all recommend that accurate sampling and testing of the material to be used should be undertaken. In accordance with these principles, Mc Keon Stone Ltd will always facilitate the collection of representative samples which prospective customers may wish to test prior to use in major projects.

Test

Units

Minimum

Typical

Maximum

Apparent Density

Kg/m3

2671

2680

2700

Porosity

% Vol.

0.43

0.48

0.54

Frost Resistance

No Effect

Capilliarity Coefficient

GC

-5.55

-6.8

-8.43

Thermal Expansion Coefficent

Mm/m.K

0.0051

0.0055

0.0058

Thermal Conductivity

W/Mk

2.5 to 3.1

Compressive Strength

N/mm2

120

136

151

Flexural Strength

N/mm2

14.2

16.8

19.8

Ultrasonic Velocity

m/s

5180

5416

5785

Scratch Test

Mm

0.3

Abrasion Resistance

Mm

18.1

18.5

19.4

Modulus of Elasticity

kN/mm2

74.85

75.24

75.97

Water Absorption

% Dry Mass

0.12

0.14

0.20

Sulphate Attack, SO2

Insensitive due to compact grain structure and extremely low iron composites content. No risk of brown discoloration and staining

Sound Insulation

Dependent on homogenous mass, large blocks of Irish Blue Limestone off good sound attenuation.

The standards used for the various tests are as follows:

Apparent Density

NBN EN 1936: 1999

Porosity

NBN EN 1936: 1999

Frost Resistance

NBN EN 12371 : 2002

Capillarity Coefficient

NBN B05-201

Thermal Expansion Coefficient

Pr EN 14581: 2004

Compressive Strength

NBN EN 1926 : 1999

Flexural Strength

NBN EN 12372 :1999

Ultrasonic Velocity

NBN B15-229

Abrasion Resistance

EN 14157: 2004

Modulus of Elasticity

PR EN14146 : 2003

Water Absorption

NBN B15-221, ASTM C97-83, BS EN 13755

The test protocols used to determine the physical properties have been given. If the values are to be used for design calculations it is important to confirm that the test cited is comparable with the relevant country standard.

Slip Resistance

Slip resistance tests were carried out using two slip measurement techniques, TRL and 4S and the results are shown below in Dry and Wet conditions. An Explanation of the values is shown in the tables below.